A printed wiring board typically has a chip capacitor mounted on its surface to achieve an efficient power supply to an IC chip. In an effort to shorten the distance between the chip capacitor and IC chip, a printed wiring board having a chip capacitor built into the board has been manufactured. Also, a printed wiring board with a built-in IC chip has been made to reduce the weight and thickness of the board and achieve a more efficient power supply.
International Publication WO 2004-089048 (hereinafter, “the '048 publication”) describes a method of manufacturing an electronic module. In this method, an electronic component is attached to a surface of a conductive layer, and a conductor is formed to connect the conductive layer and the terminals of the electronic component. A conductive pattern is formed from the conductive layer, thereby obtaining an electronic module. However, this electronic module has the following problems. The electronic component is adhered to the surface of the conductive layer such as copper foil. Copper foil is not firm and is easy to warp. A thin copper foil is harder to use, while a thick copper foil does not allow one to form fine-pitch wiring by etching. Also, if the copper foil (conductive layer) warps, the wiring in the warped section may snap, causing wiring breakage. In addition, when a via conductor for connection with a terminal of the electronic component is formed in the warped section of the copper foil (conductive layer), the connection reliability of the via conductor is reduced. The copper foil tends to warp at the time of thermosetting a resin coated on the copper foil because the resin shrinks while curing. Accordingly, the manufacturing method and the structure of the electronic module described in the '048 publication is less desirable in terms of increasing productivity.